Refactor ipfs get

License: MIT
Signed-off-by: rht <rhtbot@gmail.com>

core/commands/get.go

 package commands
 
 import (
-	"bufio"
 	"compress/gzip"
 	"errors"
 	"fmt"
@@ -11,13 +10,11 @@ import (
 	"strings"
 
 	"github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/cheggaaa/pb"
-	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
 
 	cmds "github.com/ipfs/go-ipfs/commands"
 	core "github.com/ipfs/go-ipfs/core"
 	path "github.com/ipfs/go-ipfs/path"
 	tar "github.com/ipfs/go-ipfs/thirdparty/tar"
-	uio "github.com/ipfs/go-ipfs/unixfs/io"
 	utar "github.com/ipfs/go-ipfs/unixfs/tar"
 )
 
@@ -64,15 +61,16 @@ may also specify the level of compression by specifying '-l=<1-9>'.
 			res.SetError(err, cmds.ErrNormal)
 			return
 		}
-
 		p := path.Path(req.Arguments()[0])
-		var reader io.Reader
-		if archive, _, _ := req.Option("archive").Bool(); !archive && cmplvl != gzip.NoCompression {
-			// only use this when the flag is '-C' without '-a'
-			reader, err = getZip(req.Context(), node, p, cmplvl)
-		} else {
-			reader, err = get(req.Context(), node, p, cmplvl)
+		ctx := req.Context()
+		dn, err := core.Resolve(ctx, node, p)
+		if err != nil {
+			res.SetError(err, cmds.ErrNormal)
+			return
 		}
+
+		archive, _, _ := req.Option("archive").Bool()
+		reader, err := utar.DagArchive(ctx, dn, p.String(), node.DAG, archive, cmplvl)
 		if err != nil {
 			res.SetError(err, cmds.ErrNormal)
 			return
@@ -192,42 +190,3 @@ func getCompressOptions(req cmds.Request) (int, error) {
 	}
 	return gzip.NoCompression, nil
 }
-
-func get(ctx context.Context, node *core.IpfsNode, p path.Path, compression int) (io.Reader, error) {
-	dn, err := core.Resolve(ctx, node, p)
-	if err != nil {
-		return nil, err
-	}
-
-	return utar.DagArchive(ctx, dn, p.String(), node.DAG, compression)
-}
-
-// getZip is equivalent to `ipfs getdag $hash | gzip`
-func getZip(ctx context.Context, node *core.IpfsNode, p path.Path, compression int) (io.Reader, error) {
-	dagnode, err := core.Resolve(ctx, node, p)
-	if err != nil {
-		return nil, err
-	}
-
-	reader, err := uio.NewDagReader(ctx, dagnode, node.DAG)
-	if err != nil {
-		return nil, err
-	}
-
-	pr, pw := io.Pipe()
-	gw, err := gzip.NewWriterLevel(pw, compression)
-	if err != nil {
-		return nil, err
-	}
-	bufin := bufio.NewReader(reader)
-	go func() {
-		_, err := bufin.WriteTo(gw)
-		if err != nil {
-			log.Error("Fail to compress the stream")
-		}
-		gw.Close()
-		pw.Close()
-	}()
-
-	return pr, nil
-}

fuse/readonly/readonly_unix.go

@@ -180,7 +180,7 @@ func (s *Node) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadR
 		return err
 	}
 
-	buf := resp.Data[:min(req.Size, int(r.Size()-req.Offset))]
+	buf := resp.Data[:min(req.Size, int(int64(r.Size())-req.Offset))]
 	n, err := io.ReadFull(r, buf)
 	if err != nil && err != io.EOF {
 		return err

unixfs/io/dagreader.go

@@ -58,8 +58,7 @@ type ReadSeekCloser interface {
 // node, using the passed in DAGService for data retreival
 func NewDagReader(ctx context.Context, n *mdag.Node, serv mdag.DAGService) (*DagReader, error) {
 	pb := new(ftpb.Data)
-	err := proto.Unmarshal(n.Data, pb)
-	if err != nil {
+	if err := proto.Unmarshal(n.Data, pb); err != nil {
 		return nil, err
 	}
 
@@ -70,7 +69,7 @@ func NewDagReader(ctx context.Context, n *mdag.Node, serv mdag.DAGService) (*Dag
 	case ftpb.Data_Raw:
 		fallthrough
 	case ftpb.Data_File:
-		return newDataFileReader(ctx, n, pb, serv), nil
+		return NewDataFileReader(ctx, n, pb, serv), nil
 	case ftpb.Data_Metadata:
 		if len(n.Links) == 0 {
 			return nil, errors.New("incorrectly formatted metadata object")
@@ -85,7 +84,7 @@ func NewDagReader(ctx context.Context, n *mdag.Node, serv mdag.DAGService) (*Dag
 	}
 }
 
-func newDataFileReader(ctx context.Context, n *mdag.Node, pb *ftpb.Data, serv mdag.DAGService) *DagReader {
+func NewDataFileReader(ctx context.Context, n *mdag.Node, pb *ftpb.Data, serv mdag.DAGService) *DagReader {
 	fctx, cancel := context.WithCancel(ctx)
 	promises := serv.GetDAG(fctx, n)
 	return &DagReader{
@@ -124,7 +123,7 @@ func (dr *DagReader) precalcNextBuf(ctx context.Context) error {
 		// A directory should not exist within a file
 		return ft.ErrInvalidDirLocation
 	case ftpb.Data_File:
-		dr.buf = newDataFileReader(dr.ctx, nxt, pb, dr.serv)
+		dr.buf = NewDataFileReader(dr.ctx, nxt, pb, dr.serv)
 		return nil
 	case ftpb.Data_Raw:
 		dr.buf = NewRSNCFromBytes(pb.GetData())
@@ -137,8 +136,8 @@ func (dr *DagReader) precalcNextBuf(ctx context.Context) error {
 }
 
 // Size return the total length of the data from the DAG structured file.
-func (dr *DagReader) Size() int64 {
-	return int64(dr.pbdata.GetFilesize())
+func (dr *DagReader) Size() uint64 {
+	return dr.pbdata.GetFilesize()
 }
 
 // Read reads data from the DAG structured file

unixfs/tar/writer.go

@@ -4,7 +4,6 @@ import (
 	"archive/tar"
 	"bufio"
 	"compress/gzip"
-	"fmt"
 	"io"
 	"path"
 	"time"
@@ -13,6 +12,7 @@ import (
 	cxt "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
 
 	mdag "github.com/ipfs/go-ipfs/merkledag"
+	ft "github.com/ipfs/go-ipfs/unixfs"
 	uio "github.com/ipfs/go-ipfs/unixfs/io"
 	upb "github.com/ipfs/go-ipfs/unixfs/pb"
 )
@@ -21,7 +21,8 @@ import (
 // TODO: does this need to be configurable?
 var DefaultBufSize = 1048576
 
-func DagArchive(ctx cxt.Context, nd *mdag.Node, name string, dag mdag.DAGService, compression int) (io.Reader, error) {
+// DagArchive is equivalent to `ipfs getdag $hash | maybe_tar | maybe_gzip`
+func DagArchive(ctx cxt.Context, nd *mdag.Node, name string, dag mdag.DAGService, archive bool, compression int) (io.Reader, error) {
 
 	_, filename := path.Split(name)
 
@@ -31,17 +32,44 @@ func DagArchive(ctx cxt.Context, nd *mdag.Node, name string, dag mdag.DAGService
 	// use a buffered writer to parallelize task
 	bufw := bufio.NewWriterSize(pipew, DefaultBufSize)
 
+	// compression determines whether to use gzip compression.
+	var maybeGzw io.Writer
+	if compression != gzip.NoCompression {
+		var err error
+		maybeGzw, err = gzip.NewWriterLevel(bufw, compression)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		maybeGzw = bufw
+	}
+
 	// construct the tar writer
-	w, err := NewWriter(bufw, dag, compression)
+	w, err := NewWriter(ctx, dag, archive, compression, maybeGzw)
 	if err != nil {
 		return nil, err
 	}
 
 	// write all the nodes recursively
 	go func() {
-		if err := w.WriteNode(ctx, nd, filename); err != nil {
-			pipew.CloseWithError(err)
-			return
+		if !archive && compression != gzip.NoCompression {
+			// the case when the node is a file
+			dagr, err := uio.NewDagReader(w.ctx, nd, w.Dag)
+			if err != nil {
+				pipew.CloseWithError(err)
+				return
+			}
+
+			if _, err := dagr.WriteTo(maybeGzw); err != nil {
+				pipew.CloseWithError(err)
+				return
+			}
+		} else {
+			// the case for 1. archive, and 2. not archived and not compressed, in which tar is used anyway as a transport format
+			if err := w.WriteNode(nd, filename); err != nil {
+				pipew.CloseWithError(err)
+				return
+			}
 		}
 
 		if err := bufw.Flush(); err != nil {
@@ -49,6 +77,7 @@ func DagArchive(ctx cxt.Context, nd *mdag.Node, name string, dag mdag.DAGService
 			return
 		}
 
+		w.Close()
 		pipew.Close() // everything seems to be ok.
 	}()
 
@@ -61,39 +90,32 @@ func DagArchive(ctx cxt.Context, nd *mdag.Node, name string, dag mdag.DAGService
 type Writer struct {
 	Dag  mdag.DAGService
 	TarW *tar.Writer
+
+	ctx cxt.Context
 }
 
 // NewWriter wraps given io.Writer.
-// compression determines whether to use gzip compression.
-func NewWriter(w io.Writer, dag mdag.DAGService, compression int) (*Writer, error) {
-
-	if compression != gzip.NoCompression {
-		var err error
-		w, err = gzip.NewWriterLevel(w, compression)
-		if err != nil {
-			return nil, err
-		}
-	}
-
+func NewWriter(ctx cxt.Context, dag mdag.DAGService, archive bool, compression int, w io.Writer) (*Writer, error) {
 	return &Writer{
 		Dag:  dag,
 		TarW: tar.NewWriter(w),
+		ctx:  ctx,
 	}, nil
 }
 
-func (w *Writer) WriteDir(ctx cxt.Context, nd *mdag.Node, fpath string) error {
+func (w *Writer) writeDir(nd *mdag.Node, fpath string) error {
 	if err := writeDirHeader(w.TarW, fpath); err != nil {
 		return err
 	}
 
-	for i, ng := range w.Dag.GetDAG(ctx, nd) {
-		child, err := ng.Get(ctx)
+	for i, ng := range w.Dag.GetDAG(w.ctx, nd) {
+		child, err := ng.Get(w.ctx)
 		if err != nil {
 			return err
 		}
 
 		npath := path.Join(fpath, nd.Links[i].Name)
-		if err := w.WriteNode(ctx, child, npath); err != nil {
+		if err := w.WriteNode(child, npath); err != nil {
 			return err
 		}
 	}
@@ -101,46 +123,33 @@ func (w *Writer) WriteDir(ctx cxt.Context, nd *mdag.Node, fpath string) error {
 	return nil
 }
 
-func (w *Writer) WriteFile(ctx cxt.Context, nd *mdag.Node, fpath string) error {
-	pb := new(upb.Data)
-	if err := proto.Unmarshal(nd.Data, pb); err != nil {
-		return err
-	}
-
-	return w.writeFile(ctx, nd, pb, fpath)
-}
-
-func (w *Writer) writeFile(ctx cxt.Context, nd *mdag.Node, pb *upb.Data, fpath string) error {
+func (w *Writer) writeFile(nd *mdag.Node, pb *upb.Data, fpath string) error {
 	if err := writeFileHeader(w.TarW, fpath, pb.GetFilesize()); err != nil {
 		return err
 	}
 
-	dagr, err := uio.NewDagReader(ctx, nd, w.Dag)
-	if err != nil {
-		return err
-	}
-
-	_, err = io.Copy(w.TarW, dagr)
-	if err != nil && err != io.EOF {
-		return err
-	}
-
-	return nil
+	dagr := uio.NewDataFileReader(w.ctx, nd, pb, w.Dag)
+	_, err := dagr.WriteTo(w.TarW)
+	return err
 }
 
-func (w *Writer) WriteNode(ctx cxt.Context, nd *mdag.Node, fpath string) error {
+func (w *Writer) WriteNode(nd *mdag.Node, fpath string) error {
 	pb := new(upb.Data)
 	if err := proto.Unmarshal(nd.Data, pb); err != nil {
 		return err
 	}
 
 	switch pb.GetType() {
+	case upb.Data_Metadata:
+		fallthrough
 	case upb.Data_Directory:
-		return w.WriteDir(ctx, nd, fpath)
+		return w.writeDir(nd, fpath)
+	case upb.Data_Raw:
+		fallthrough
 	case upb.Data_File:
-		return w.writeFile(ctx, nd, pb, fpath)
+		return w.writeFile(nd, pb, fpath)
 	default:
-		return fmt.Errorf("unixfs type not supported: %s", pb.GetType())
+		return ft.ErrUnrecognizedType
 	}
 }